Exemplary embodiments of the present invention relate to a radar apparatus, and more particularly, to a radar apparatus supporting short and long range radar operations capable of implementing miniaturization, high integration, and low power consumption by implementing most components in the radar apparatus on a single chip while supporting a short range radar operation and a long range radar operation by a single apparatus or system configuration.
A background art of the present invention is disclosed in Korean Patent Laid-Open Publication No. 2009-0067990 (Published in Jun. 25, 2009).
Recently, as a demand for a short range high resolution radar in a millimeter/sub-millimeter band is increased, a study therefor has been continued. The high resolution radar system capable of discriminating or decomposing a distance between proximity objects has been variously used as industrial, military applications, and the like, and has been mainly used for a radar system for a vehicle in a real life. The radar system for a vehicle, which is an essential technology for implementing an intelligent traffic system, may mean a safety driving system of a vehicle developed so as to previously prevent accidents occurring due to poor weather conditions or carelessness of a driver by sensing motions of other vehicles or objects that move or stop within a radius of about 250 m or less.
The high resolution radar system in accordance with the related art detects objects in all directions by scanning objects with a precise mechanical apparatus so as to obtain the high spatial resolution within a small field of view. However, when the number of antennas is increased so as to increase the spatial resolution, a size of the mechanical apparatus is large. Therefore, a multi-beam antenna and a digital beamforming technology that can implement electrical scanning have been used, which are mainly applied to, in particular, a small radar for a vehicle.
The radar technology for a vehicle may be classified into a long range radar (LRR) capable of being sensed up to about 250 m or less and a short range radar (SRR) capable of being sensed up to about 60 m or less. In the case of the LRR, a frequency of a 77 GHz band has been mainly used and in the case of the SRR, a frequency of a 24 GHz band has been mainly used. The radar apparatus for a vehicle in accordance with the related art has a limitation in simultaneously applying an LRR mode having a relatively long detection range and a narrow field of view according to each application and an SRR mode having a short detection range or a wide field of view to a single apparatus or system.
FIG. 1 illustrates an example of a configuration of a radar apparatus in accordance with the related art; The radar apparatus in accordance with the related art illustrated in FIG. 1 adopts a structure in which a transmitter 103 can perform beamforming and time division and a receiver 107 can receive nine channel data to reduce the number of antennas 104 and 105, thereby implementing miniaturization. However, the radar apparatus in accordance with the related art illustrated in FIG. 1 may perform only one of the long range radar operation or the short range radar operation and thus, cannot simultaneously implement the long and short range radar modes.
Further, the radar apparatus in accordance with the related art of FIG. 1 adopts a structure of using a switch to sequentially receive signal from an array antenna. However, the switch needs to have excellent isolation characteristics. These characteristics can be implemented only by a compound element. The current CMOS technology is hard to implement the excellent isolation characteristics, such that there is a limitation in implementing the transmitting and receiving radar apparatus in a single chip type by using the CMOS technology. To the present, the radar of the long range and short range applications for a vehicle has been commercialized. However, the radar is expensive, consumes large power, and has a large volume, which leads to a limitation in being simultaneously mounted in the front, rear, and sides of all the vehicles. Recently, an SiGe technology has been used to implement miniaturization through integration, but makes it more difficult to implement low power consumption than the CMOS technology and has a limitation in implementing miniaturization or low price due to a large antenna.